Problem 2. (10 points)
The matrices are
$A = \begin{pmatrix} 2 & 0 \\ 0 & 4 \end{pmatrix}$, $B = \begin{pmatrix} 0 & -3 \\ 1 & 0 \end{pmatrix}$, $C = \begin{pmatrix} 2 & 1 & 0 \\ 0 & 1 & -2 \\ 0 & 0 & 2 \end{pmatrix}$.
Compute the following quantities. If a calculation is invalid or the result does not exist, just say \"DNE\".
(1) 2A-B, (2) A*B, (3) B*A, (4) $B^{-1}$, (5) det(C).